Telephone system



Feb. 12 1924.

R. s. WILBUR TELEPHONE SYSTEM Filed D90, 31 1.9.19

W e/775W." Ray \5. l M'Zbur y w AW v Patented Feb. 12, 1924.

UNITED STATES PATENT OFFICE.

RAY s. WILBUR, *or LYNDHUBST, new annsnr, Assrenon :ro Wns'rnnn'nrnc'rnro coMPnnY, mconr'onarnn, or NEW atoms, is. r, a oonronarron' ornew roan.

TELEPHONE Application filed December 31, 1919. Serial No. 348,585.

To all whom it may concern Be 1t known that I, RAY S. WILBUR, a

citizen of the United States, residing at Lyndhurst, in the county ofBergen, State of New Jersey, have invented certain new and usefulImprovements in Telephone Systems, of which the following is a full,clear concise, and exact description.

This invention relates to improvements in signaling systems and hasparticular reference to a composite ringing repeater circuit employed intoll transmission lines.

In the transmission of signaling current in composite repeater circuits,it has been customary to connect relays directly across an incoming lineor through amplifiers, which relays are tuned to respond to currents ofhigh and low alternating current frequencies for the purpose ofoperating signals at the terminating ends of the line. It has been foundin practice that the nature of the current flowing through the windingsof these relays is such as to cause a constant vibrationof thearinatures there of, which tends to decrease the efficiency of operationAn object of the present invention is to provide an improved means foraccomplislr ing the transmission of signaling current to the terminatingend of a repeater circuit, wherein the vibrations, above referred to,are eliminated and the operation thereby rendered more positive.

The drawing illustrates diagrammatically the terminating end of acomposite ringing repeater circuit showing a preferred application ofthe invention thereto.

Inthe drawing, the numerals 1 and 2 indicate the sides of a tolltransmission line, the ends of which terminate in the tip and ringcontacts of a ack 3. For the purpose of preventing; the passage of il33-cyclc altermating current through the ten'minatinp ends of thetransmission line, filters at are bridged across the sides 1 and 2 ofthe line.

In the present invention, a pair of repeaters or amplifiers 5 and 6 ofthe well known dischargetube type are connected to the sides 1 and 2 ofthe transmission line respectively through input coils 7 and 8, andarranged between these input coils of the lines arethe retardation coils9 which eX- elude low frequency currents froiiithe repeaters. Signalingcurrent of 183 cycles,

incoming on the line is prevented from passing thereover to theterminating end of the line by the filters 4e, and consequently thiscurrent will flow through the retardation coils 9 and the input coils 7and 8 of peaters 5 and 6. It is proposed to splitthe phase of thealternating current incoming; on the transmission line in order that thealternating current will be alternately induced into the repeaters. Forthis purpose a condenser 10 is preferably connected in parallel with theprimary winding of the input coil 8 and thereby establishes a localoscillating circuit including the primary winding; of the input coil 8,In thus splitting the phase of thisalternating current it will beapparent that the same will be first induced into the input side oftherepeater 5 and then into the input side of repeater (5. thusmaintaining a constant flow of current which is alternately amplified bysaid re peaters.

The constant flow of the current to the repeaters 5 and 6 is utilized tomaintain the energization of relay 11 during the application of ringingcurrent to the incoming end of the transmission line. The relay 11 isresponsive to direct current which, in one instance, flows from thepositive pole of battery, through the lefthand winding of relay 11,theplate of repeater 5, and to groun d through the filament of therepeater. In the case of the repeater ('3, a circuit for relay 11extends from battery, through the right-hand winding of said relay, theplate of repeater G, tothe filament of said repeater and thepotentiometer 12 to the negative pole of battery.

It will thus be apparent that relay 11 will remain constantly energizedby dirert currenttlowing through the windings thereof and the outputside of the repeaters 5 and 6 when alternating" current of 133 cycles ispassed through said repeaters. The energization of relay 11 closes acircuit extending from ground, through the contact of said relay and thewinding of relay 13, to grounded battery. Relay 13 energizes and at itsnormal contacts disconnects the sides'l and 2 of the transmission linefrom the jack 3 during the application ofringing current to the line. Byclosing its alternate contacts,

relay 13 establishes a circuit entendingfronn its the source of ringingcurrent, preferably of 16% cycles, through the lower alternate contactof relay 13, the ring contact of jack 3, the Winding of signaling device14, the tip contact of jack 3, and the upper alternate contact of relay13, to ground. Signaling device 14 is responsive to this signalingcurrent and operates to indicate to the operator at the terminating endof the transmission line that a call is being extended thereover,whereupon the operator inserts the plug of a link circuit into jack 3and thereby disconnects the signaling device 1 1 from the terminatingend of the'line. When transmission of signaling current through therepeaters 5 and 6 ceases, relay 11 releases and opens the energizingcircuit for relay 13 which again connects the sides 1 and 2 of thetransmission line to the terminating ends thereof. Conversation may thenproceed over the line.

When ringing out over the sides of the line the insertion of a plug intojack 8 and the operation of the ringing key of the link circuitconnected to said jack causes the energization of relay 15, which, inclosing its contact, establishes an obvious circuit for relay 16. Thisrelay energizes and at its alternate contact connects the source ofsignaling current 17, preferably of 133 cycles, to the sides of the line1 and 2 and the transmission of this signaling current to the otherterminating end of the line will be effected in the same manner asdescribed in connection with transmission of signaling current to theend of the line shown in the drawing.

What is claimed is:

1. In a signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, asource of alternating current, means for connecting said source of alternating current to the terminating end of said line, and means responsiveto and maintained effective by direct current through said re peatersfor operating the last named means during the transmission ofalternating current over said line.

2. In a signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, asource of alternating current, means for connecting said source ofcurrent to. the terminating end of said line, and a relay connected tothe output sides of said rgtpeaters and responsive to and maintained eective by direct current therefrom for op erating said means during thetransmission of alternating current over said line.

3. Ina signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, arelay responsive to direct current transmitted from said repeatersduring the transmission of alternating current incoming on said line,means on the input side of said repeaters fo' alternately rendering thesame effective to apply direct current to said relay whereby the relayis constantly maintained energized. and means responsive to theenergization of said relay for applying alternating current to theterminating end of said line.

4. In a signaling system, a transn'iission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, anelectromagnetic device responsive to direct current from said repeaters,an input coil for each repeater, means for splitting the phase of thealternating current passing through said coils to said repeaters forconstantly maintaining the energization of said electromagnetic deviceand means responsive to the energization of said device for applyingalternating current to the terminating end of said line.

5. In a signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, arelay having windings each of which is connected to the output side ofone ofsaid repeaters, an input coil for each repeater, means connectedto the coil of one repeater for splitting the phase of alternatingcurrent incoming on said line whereby said repeaters are alternatelylCl'h dered effective to constantly supply direct current to thewindings of said relay, and means responsive to the energization of saidrelay for applying alternating current to the terminating end of saidline.

6. In a signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, alocal circuit for the input coil of one repeater, a condenser connectedto a winding of the input coil of the other repeater for establishingsaid local circuit, a relay connected to the output sides of saidrepeaters and maintained constantly energized during the transmission ofalternating current through said repeaters by direct current transmittedalternately therefrom, and means responsive to the energization of saidrelay for applying alternating current to the terminating end of saidline.

7. In a signaling system, a transmission line, repeaters connected tosaid line for amplifying alternating current transmitted thereover, asource of alternating current, means for connecting said source ofcurrent to the terminating end, of said line, and means responsive onlyto direct current-through said repeaters and maintained effective bysaid direct current for operating the first-named means during thetransmission of alternating current over said line.

8. In a signaling system, a transmission line, repeaters comiected tosaid line for amplifying alternating current transmitted thereover, asource of alternating current, means for connecting said source to theterminating end of said line, and a switching device connected to theoutput sides of said repeaters and responsive only to direct currentfrom said repeaters and main tained operated by said direct current foractuating said means during the transmission of alternating current oversaid line.

In Witness whereof, I hereunto subscribe my name this 30th day ofDecember A. D.

RAY S. Vlfltlililllt.

